Microsoft posts five critical fixes in monthly update

Microsoft has released five critical updates, including patches for remote code execution vulnerabilities in Windows and Internet Explorer, in its February security update.

The company said that the two Internet Explorer updates should be viewed by administrators as top priorities for testing and deployment. A third update, this time for Windows XP SP3, should also be considered a top deployment priority.

The remaining two critical bulletins, which patch flaws in the Windows Exchange and DirectShow components, are being classified by Microsoft is lower priority deployments.

Along with the five critical bulletins, the company posted seven fixes which have been classified as 'important' releases and have been given lower deployment priorities than the the critical bulletins. The updates include fixes for flaws in Office, Windows and the .NET Framework.

Marc Maiffret, chief technology officer for security firm BeyondTrust, noted that a number of the bulletins address publicly-disclosed flaws, thus heightening the possibility for active exploit by attackers in the wild.

"This month brings along fixes for multiple publicly disclosed vulnerabilities," he said.

"It should be noted that Microsoft lists vulnerabilities previously fixed in third-party products as publicly disclosed, even though these vulnerabilities have not necessarily been directly disclosed by researchers or observed being exploited in the wild."

Microsoft is also advising users to install security tools which can lower the effectiveness of drive-by malware attacks. Response communications manager Dustin Childs said in a company blog post that the free Enhanced Mitigation Experience Toolkit (EMET) can provide extra protections.

"If you are not familiar with EMET, it provides security mitigation technologies to make it more difficult for an attacker to exploit vulnerabilities in existing software – even those issues that are unknown," he explained.

"EMET does this by stopping known exploit techniques and allowing applications to opt-in to existing mitigations that already exist on your system, like Data Execution Prevention (DEP) and Address Space Layout Randomization (ASLR)."